title: The relation of pericoronal third molar follicle dimension and bcl-2/ki-67 expression: An immunohistochemical study.
abstract: BACKGROUND
  Most common impacted teeth are the mandibular third molars and decision about extraction of them is usually controversial. The presence of pericoronal pathologic changes is an acceptable reason for removal of impacted teeth. Differences in the proliferation rate and apoptosis of odontogenic epithelial cells may influence on the formation of odontogenic epithelial lesions. Therefore, the aim of the present study is to evaluate the immunohistochemical expression of the bcl-2 apoptosis-inhibiting protein and the cell-cycle-related ki-67 antigen in pericoronal follicle of impacted third molars with ≥2.5 mm and <2.5 mm radiolucency.
  
  
  METHODS
  This was a cross-sectional study that 20 follicles with <2.5 mm radiolucency and 20 follicles with ≥2.5 mm radiolucency were selected by a professional radiologist in digital panoramic radiographs and then referred to a surgeon. Formalin fixed paraffin-embedded tissues were immunohistochemical analyzed for immunoreactivity of bcl-2 protein and ki-67 antigen. The data was analyzed using logistic regression, Spearman correlation coefficient and t-test and Mann-Whitney. P<0.05 was considered significant.
  
  
  RESULTS
  The findings showed correlation between size of the third molar's follicles and expression of bcl-2 protein (P < 0.001, r = 0.556) but there was no correlation between size of third molar's follicles and staining with ki-67 antigen (P = 0.546, r = 0.098). The follicles with radiolucency ≥2.5 mm showed increased immunoreactivity for bcl-2 protein.
  
  
  CONCLUSIONS
  The results of study suggest that impacted third molars with radiolucency ≥2.5 mm may be associated with deregulation of cell death, indicated with increased expression of the anti- apoptotic protein bcl-2, while cell proliferation (ki-67) does not seem to play a significant role.
authors.affiliation: Torabinejad Dental Research Center and Department of Oral and Maxillofacial Pathology, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Seyed Mohammad
authors.initials: SM
authors.lastname: Razavi
authors.forename: Daryush
authors.initials: D
authors.lastname: Hasheminia
authors.forename: Mojde
authors.initials: M
authors.lastname: Mehdizade
authors.forename: Bijan
authors.initials: B
authors.lastname: Movahedian
authors.forename: Forouz
authors.initials: F
authors.lastname: Keshani
keywords: Apoptosis; bcl-2 antiapoptotic protein; immunohistochemistry; ki-67 antigen; third molar